Surveillance video shows the suspect just moments before the murder of Alla Kamenev.
He is seen riding a girl's bike with a red basket.
Detectives believe the suspect is his 50s.
Officers say the suspect shot Kamenex three times just before noon on Thursday as she stood outside a park in /*Brighton Beach*/.
She died at the hospital a short time later.
Police do not have a motive for the attack.
